Buggy code:
public class FieldUtils { public FieldUtils ( ) { } public static Field getField ( Class cls , String fieldName ) { } public static Field getField ( final Class cls , String fieldName , boolean forceAccess ) { if ( cls == null ) { throw new IllegalArgumentException ( "The<seq2seq4repair_space>class<seq2seq4repair_space>must<seq2seq4repair_space>not<seq2seq4repair_space>be<seq2seq4repair_space>null" ) ; } if ( fieldName == null ) { throw new IllegalArgumentException ( "The<seq2seq4repair_space>field<seq2seq4repair_space>name<seq2seq4repair_space>must<seq2seq4repair_space>not<seq2seq4repair_space>be<seq2seq4repair_space>null" ) ; } for ( Class acls = cls ; acls != null ; acls = acls . getSuperclass ( ) ) { try { Field field = acls . getDeclaredField ( fieldName ) ; if ( ! ( Modifier . isPublic ( field . getModifiers ( ) ) ) ) { if ( forceAccess ) { field . setAccessible ( true ) ; } else { continue ; } } return field ; } catch ( NoSuchFieldException ex ) { } } Field match = null ; for ( Iterator intf = ClassUtils . getAllInterfaces ( cls ) . iterator ( ) ; intf . hasNext ( ) ; ) { try { Field test = ( ( Class ) ( intf . next ( ) ) ) . getField ( fieldName ) ; if ( match != null ) { <START_BUG> throw new IllegalArgumentException ( ( ( ( ( "Reference<seq2seq4repair_space>to<seq2seq4repair_space>field<seq2seq4repair_space>" + fieldName ) + "<seq2seq4repair_space>is<seq2seq4repair_space>ambiguous<seq2seq4repair_space>relative<seq2seq4repair_space>to<seq2seq4repair_space>" ) + cls ) + ";<seq2seq4repair_space>a<seq2seq4repair_space>matching<seq2seq4repair_space>field<seq2seq4repair_space>exists<seq2seq4repair_space>on<seq2seq4repair_space>two<seq2seq4repair_space>or<seq2seq4repair_space>more<seq2seq4repair_space>parent<seq2seq4repair_space>interfaces." ) ) ; <END_BUG> } match = test ; } catch ( NoSuchFieldException ex ) { } } return match ; } public static Field getDeclaredField ( Class cls , String fieldName ) { } public static Field getDeclaredField ( Class cls , String fieldName , boolean forceAccess ) { } public static Object readStaticField ( Field field ) throws IllegalAccessException { } public static Object readStaticField ( Field field , boolean forceAccess ) throws IllegalAccessException { } public static Object readStaticField ( Class cls , String fieldName ) throws IllegalAccessException { } public static Object readStaticField ( Class cls , String fieldName , boolean forceAccess ) throws IllegalAccessException { } public static Object readDeclaredStaticField ( Class cls , String fieldName ) throws IllegalAccessException { } public static Object readDeclaredStaticField ( Class cls , String fieldName , boolean forceAccess ) throws IllegalAccessException { } public static Object readField ( Field field , Object target ) throws IllegalAccessException { } public static Object readField ( Field field , Object target , boolean forceAccess ) throws IllegalAccessException { } public static Object readField ( Object target , String fieldName ) throws IllegalAccessException { } public static Object readField ( Object target , String fieldName , boolean forceAccess ) throws IllegalAccessException { } public static Object readDeclaredField ( Object target , String fieldName ) throws IllegalAccessException { } public static Object readDeclaredField ( Object target , String fieldName , boolean forceAccess ) throws IllegalAccessException { } public static void writeStaticField ( Field field , Object value ) throws IllegalAccessException { } public static void writeStaticField ( Field field , Object value , boolean forceAccess ) throws IllegalAccessException { } public static void writeStaticField ( Class cls , String fieldName , Object value ) throws IllegalAccessException { } public static void writeStaticField ( Class cls , String fieldName , Object value , boolean forceAccess ) throws IllegalAccessException { } public static void writeDeclaredStaticField ( Class cls , String fieldName , Object value ) throws IllegalAccessException { } public static void writeDeclaredStaticField ( Class cls , String fieldName , Object value , boolean forceAccess ) throws IllegalAccessException { } public static void writeField ( Field field , Object target , Object value ) throws IllegalAccessException { } public static void writeField ( Field field , Object target , Object value , boolean forceAccess ) throws IllegalAccessException { } public static void writeField ( Object target , String fieldName , Object value ) throws IllegalAccessException { } public static void writeField ( Object target , String fieldName , Object value , boolean forceAccess ) throws IllegalAccessException { } public static void writeDeclaredField ( Object target , String fieldName , Object value ) throws IllegalAccessException { } public static void writeDeclaredField ( Object target , String fieldName , Object value , boolean forceAccess ) throws IllegalAccessException { } }

Fix:
throw new IllegalArgumentException ( ( ( ( ( "Reference<seq2seq4repair_space>to<seq2seq4repair_space>field<seq2seq4repair_space>" + fieldName ) + "<seq2seq4repair_space>is<seq2seq4repair_space>ambiguous<seq2seq4repair_space>relative<seq2seq4repair_space>to<seq2seq4repair_space>" ) + cls ) + ";<seq2seq4repair_space>a<seq2seq4repair_space>matching<seq2seq4repair_space>field<seq2seq4repair_space>exists<seq2seq4repair_space>on<seq2seq4repair_space>two<seq2seq4repair_space>or<seq2seq4repair_space>more<seq2seq4repair_space>implemented<seq2seq4repair_space>interfaces." ) ) ;